The recovery effort in Surfside, Fla., continues at the site of a condo building collapse that killed at least 86 people and left dozens more others unaccounted for.

Engineers have begun investigating the cause of the collapse, but officials say determining what led the 40-year-old 12-story building to partially fall will take time.

Here’s what you need to know about the situation:

What to know

  • What do we know about the collapse?
  • Are people still searching for survivors?
  • Was anyone rescued from the collapsed building?
  • What caused the collapse?
  • Is there any information about the victims?